* tree-parloops.c: New file.
	* tree-ssa-operands.h (free_stmt_operands): Declare.
	* tree-ssa-loop-manip.c (split_loop_exit_edge): Return the new basic
	block.
	* tree-pass.h (pass_parallelize_loops): Declare.
	* omp-low.c (expand_omp_parallel, expand_omp_for): Update SSA form for
	virtual operands.
	(build_omp_regions_1): Allow analysing just a single OMP region and
	its subregions.
	( build_omp_regions_root, omp_expand_local): New functions.
	(build_omp_regions): Add argument to build_omp_regions_1 call.
	* builtins.def (DEF_GOMP_BUILTIN): Initialize OMP builtins when
	autoparallelization is run.
	* timevar.def (TV_TREE_PARALLELIZE_LOOPS): New.
	* tree-ssa-loop.c (gate_tree_parallelize_loops, tree_parallelize_loops,
	pass_parallelize_loops): New.
	* common.opt (ftree-parallelize-loops): New.
	* tree-flow.h (omp_expand_local, tree_duplicate_sese_tail,
	parallelize_loops): Declare.
	(add_phi_args_after_copy, split_loop_exit_edge): Declaration changed.
	* Makefile.in (tree-parloops.o): Added.
	* tree-cfg.c (add_phi_args_after_copy_edge, tree_duplicate_sese_tail):
	New functions.
	(add_phi_args_after_copy_bb): Use add_phi_args_after_copy_edge.
	(add_phi_args_after_copy): Call add_phi_args_after_copy_edge for
	one extra edge as well.
	(tree_duplicate_sese_region): Add argument to add_phi_args_after_copy.
	Use VEC_free to free doms vector.
	(move_block_to_fn): Update loop info. Remove phi nodes for virtual
	operands.  Recompute operand caches in the new function.
	(move_sese_region_to_fn): Update loop info.
	* passes.c (init_optimization_passes): Add pass_parallelize_loops.
	* tree-ssa-operands.c (free_stmt_operands): New function.

	* doc/passes.texi: Document autoparallelization.
	* doc/invoke.texi (-ftree-parallelize-loops): New option.

	* gcc.dg/tree-ssa/parallelization-1.c: New test.

From-SVN: r128517